Study of the performance of a group of quadrupole mass spectrometers

Abstract

Results are presented from a series of experiments that were designed to characterise quadrupole analyzers. Three different analyzers have been studied. The first, typical of the small quadrupoles often used for residual gas analysis, has rods 50 mm long and 6.25 mm in diameter. The second uses rods of similar diameter, but 125 mm long. The third uses rods of diameter 12 mm and length 230 mm. Simple ion sources were used. All had cylindrical ionization regions with external filaments, in a configuration similar to an extractor ion gauge. All were operated under similar conditions. The sensitivity and linearity of the instrument is found to depend in a complex way on the operating conditions of the ion source. The observed behavior is explained qualitatively by the presence of both electronic and ionic space charge in the ion source.

A Method of Computing Accurate 3D Fields of a Quadrupole Mass Filter and Their Use for Prediction of Filter Behavior

“…Hence, the actual filter transmission value cannot be determined experimentally although variation in transmission can be measured over a small range of ion velocity. There are few quantitative studies of ion source behavior; those there are, for example [29], show that behavior is complicated and output may vary with ion mass, ion energy, ion type and even with time.…”

Time stability characterization of quadrupole mass spectrometers

“…Alper Elkatmis 1 , Janez Setina 2 , Rifat Kangi 1 , Ute Becker 3 , Karl Jousten 3 , Domenico Mari 4 , Frederic Boineau 5 , Martin Vicar 6 , Salustiano Ruiz 7 1 TÜBİTAK UME National Metrology Institute, 41470 Gebze, Turkey, 2 Institute of Metals and Technology, (IMT), Ljubljana, Slovenia, 3 Physikalisch Technische Bundesanstalt (PTB), Berlin, Germany, 4 Istituto Nazionale di Ricerca Metrologica (INRIM), Torino, Italy, 5 Laboratoire National de Métrologie et d'Essais (LNE), Paris, France, 6 Czech Metrology Institute, (CMI), Brno, Czech republic, 7 Centro Español de Metrología, (CEM), Madrid, Spain Email of corresponding author: alper.elkatmis@tubitak.gov.tr Quadrupole Mass Spectrometers (QMSs) are widely used in industry for many applications such as leak detection, diagnostic purposes, qualitative and quantitative measurements in vacuum processes. This study focuses on the measurements of time stability of metrological characteristics including sensitivity using Faraday cup as a detector, mass scale, mass resolution, secondary electron multiplier (SEM) gain and minimum detectable partial pressure (MDPP) of QMSs.…”

“…The operation of RGAs requires optimal selection of the several functional parameters and proper use of RGAs has been discussed in previously published studies [3][4][5][6]. Participant-6 studied two identical QMSs equipped with two filaments identified as QMS6-1, QMS6-2 and QMS7-1 and QMS7-2.…”

Addressing challenges with evaluating hydrogen‐selective membrane performance by quadrupole mass spectrometry

“…Ever since the factors that cause sensitivity instability of quadrupole mass spectrometers have been reported, 15–19 calibration of such instruments for quantitative analysis of gas mixtures has also been discussed in the literature 20–28 . Regarding hydrogen‐containing mixtures, our literature survey revealed that the interference effect was studied for mixtures of: Ar and H 2 20,21,28,29 ; H 2 , Ne, and Ar 21 ; N 2 and H 2 28,30 ; He and H 2 28 ; Ar and a mixture of H 2 , CO, and CO 2 28 ; a series of H 2 , CO, and CO 2 with a mixture of He, N 2 , and Ar 17 ; and H 2 , O 2 , and CO 2 mixtures 20 .…”

“…Ever since the factors that cause sensitivity instability of quadrupole mass spectrometers have been reported, [15][16][17][18][19] calibration of such instruments for quantitative analysis of gas mixtures has also been discussed in the literature. [20][21][22][23][24][25][26][27][28] Regarding hydrogen-containing mixtures, our literature survey revealed that the interference effect was studied for mixtures of: Ar and H 2 20,21,28,29 was used as a second trace gas alongside the same interfering gases, CO and CO 2 .…”